Method and means for preventing rapid formation of frost on refrigerating conduits



Jul 3, 1934.. G. H. KLIPPEL METHOD AND MEANS FOR PREVENTING RAPIDFORMATION OF FROST ON REFRIGERATING CONDUITS M M W W M Filed June 17,1932 ATTORNES.

INVENTOR WWW Patented July 3, 1934 UNITED STATES PATENT OFFICE METHODAND MEANS FOR PREVENTING RAPID FORMATION OF FROST ON REFRIG- ERATIN GCONDUITS This invention has for its object, a method and means forpreventing the rapid formation of frost on the refrigerator pipes orconduits of refrigerators.

In refrigerators, such as are used in food stores and markets etc., itis necessary to periodically defrost the refrigerator conduits, orcoils, that is,

a the coils through which the brine or other refrigerating medium iscirculated. This requires several hours, and sometimes as long as twodays, and a shutting down of the refrigerator plant for that period. Thefrost and ice is filthy and contaminates the food products, and the foodproducts are liable to spoil, or deteriorate during the cleaningprocess. Also, when frost'forms on the coils, moisture is withdrawn fromthe contents of the refrigerator. Meats become slimy, and vegetablesdry. This condition increases as the frost and ice forms. Or, in otherwords, the frost is formed from moisture absorbed from the meat, orother food, stored in the refrigerator, and due to the absorption themeat, or food, deteriorates, and hence, in the refrigerators heretoforeused, the meat, or food, deteriorates in the normal operation of therefrigerator.

It has been customary to circulate air more or less haphazard fashionthrough the refrigerator, but the ordinary circulation aggravates theconditions. That is, it does not keep the conduits from frosting, norprevent the absorption of moisture from the food, as in the circulatingsystem, the refrigerated air being heavier leaves the coils by gravityand hence, hovers around the coils long enough for the moisture tofreeze on the coils.

The object of my invention is an air circulating system, or means forcirculating the air. The refrigerated air is moved from the coilscontinuously against gravity, without blowing directly against the coilsso that the warmen air from the interior of the refrigerator room passescontinuously by convection among, or between the coils.

The method therefore consists in moving the body of air upwardly throughthe coils then downwardly at one side of the coils from the upperportion of the refrigerator to the lower part thereof where the food orcontents are stored so that the warmer air moves slowly or almost byconvection upwardly between or among the coils at such a rate of speedthat the air is chilled, but a large portion thereof does not contactthe coils and hence, very little condensation deposited on the coils,which condensation is removed when the ice machine shuts down under itsthermostatic control. A fan, or a blower creates an air current ofsuilicient force to create a moving body of air above and transverselyof the coils so that its action lifts, injector fashion, some of the airslowly and without undue turbulence through the coils.

The apparatus consists in the relative arrangement of coils in therefrigerator room, or cabinet, 00 and the fan, or blower, and in themethod and combination and construction hereinafter set forth andclaimed.

In describing this invention, reference is had to the accompanyingdrawing, in which like charac- 5 ters designate corresponding parts inall the views.

Figure 1 is a vertical, sectional view through a refrigerator room, orcabinet, embodying one form of my invention.

Figure 2 is a side elevation of the blower.

I have here shown my invention as applied to a refrigerator room, orcabinet, such as is ordinarily used in grocery stores and meat markets.

1 designates the room, or cabinet, which includes a top wall 2, oppositeside walls 3, 4, and front and rear walls, one of which is provided witha door 5. The cabinet, or room, is closed, except when the door isopened to enter or leave the cabinet or 'room.

'7 and 8 designate coils, or conduits, for a refrigerating medium, orthrough which the medium circulates, and 9 are pans having shields 9extending between the side walls 3 and 4, and the coils with the pansextending under the coils. The cabinet coils and pans are the same as inany refrigerating cabinet, such as are used in stores and meat markets.Ordinarily, the coils become gradually covered with frost, and the coilsmust be defrosted periodically. The defrosting operation is an expensiveand filthy operation which heretofore has been necessary andunavoidable. It requires a shutting down of the refrigerating plant forseveral hours, and results in deterioration, if not complete spoiling ofthe contents of the refrigerator. If not defrosted periodically, therefrigerator will not function efiiciently.

10 designates a blower of any suitable construction located near the topof the cabinet, or room, and midway between the coils '7 and 8, theblower having outlets directed laterally over the tops of the coils, ortoward the space between the coils and the top wall. The blower also hasa suitable intake at 11, this being also located between the coils. Ashere shown, the blower is provided at its discharge end with an airsplitter or deflector 1.2, this air splitter being adjustable laterallyno to adjust the amount of air current that is deilected in oppositedirections.

The rotor of the blower is actuated in any suitable manner. as by anelectric motor 13. The splitter is here shown as adjustable along meansas transverse flanges 14 at the outlet of the blower, and held inadjusted position by bolts 15, or other clamping means, the flangesbeing formed with a series of holes 16 for the bolts.

In operation, the blower discharges air through its outlet against thedeflector, or splitter, from which it passes laterally through passages1'7 between the top wall 2 and the coils '7, then downward assisted bygravity through passages 18 between the side walls 3, 4, and the coils,and thence throughout the lower part of the refrigerator where the foodis stored, where it absorbs heat, then upwardly and by convectionbetween the coils, most of the upward air current being taken in at thefan and recirculated, but some of it moving between or about the coils.The air current created by the fan keeps the body of air in the cabinetin motion throughout a definite path, and prevents the air from hoveringaround the pipes.

The air current is of suflrlcient force to push against the body of airin the passage 1'? and displace it laterally in the passage 18 where itfalls by gravity. This lateral displacement causes the warmer air torise by convection through, or around the coils where it becomesrefrigerated and heavier, but prevented from falling or hovering aboutthe coils. The action of the forced draft created by the fan on thebodyof air above the coils in the passage 17 causes a suction, or ejectoraction among the coils, so that the air being cooled flows slowly butcontinuously among the coils.

The flow of the brine, or other refrigerating medium through the coilsis adjusted for maintaining the desired temperature, and the movement ofthe air current regulated by means of an adjustable shutter 19 at theintake of the blower. The fan forces air in a path around eachrefrigerating unit and, out of contact with the same causingrefrigerated air about the conduits of each refrigerating unit to besucked upwardly against gravity through the refrigerating unit by theejector action of the air passing horizontally over the top of therefrigerating unit. The refrigerated air from the refrigerating unitmixes with the unrefrigerated air as the same enters and passes downwardthrough the side passage18 to the lower portion of the refrigeratorbefore the mixed refrigerated and unrefrigerated air comes in contactwith the food products and other contents of the refrigerator. The airwarmed by the food products and other contents of the refrigeratorpasses upward to the fan and to the coils of the refrigerating units.The fan in circulating the air draws most of the air through it but someof the warmed air passes upward through the refrigerating unit toreplace the refrigerated air removed from the refrigerating unit by theejector action of the forced air passing over the top of the unit. Dueto this action of the fan in creating these currents rapid formation offrost is prevented because only a portion of the air contacts with thecoils and the refrigerated air does not have a chance to hover aroundthe coils but passes upward through the same through the said ejectoraction of the forced unrefrigerated air passing over the coils..

Some of the air passing upward through the refrigerating unit does notcome in contact with the coils and retains some of its moisture. Alsothe air passing through the fan and discharged in a transverse currentover the refrigerating unit and not coming in contact with the coilsthereof retains its moisture so that the mixed unrefrigerated air andrefrigerated air passing downward through the side passage 18 is not asdry as the air would be if all of the air came in contact with therefrigerating coils and the circulation of the mixed air through thefood products will not have the drying effect on the same asrefrigerated air from which all of the moisture has been removed throughcontact with refrigerating coils. In operation, the shutter 14 isusually adjusted so that a suilicient amount of air is circulated toprevent the formation of frost on the coils at all times, but if desiredthe air circulation may be regulated by the adjustment of the shutter sothat there will be a slight formation of frost onthe coils during theoperation of the compressor of the ice machine, which frost will beabsorbed by the air circulation when the compressor shuts off by itsthermostatic control. My invention is particularly advantageous inrefrigerators such as are used in meat markets and grocery and generalproduce stores where a temperature of above and near freezing ismaintained.

My invention, although simple, entirely and satisfactorily solves a longexistent problem in the refrigerator art, particularly in connectionwith refrigerators used in meat markets, stores etc., and permits the,refrigerator system to be operated without stopping and withoutvariations in temperature of more than a one-half degree during theentire operation, and further avoids the inconvenience of frequentstopping of the refrigerator to defrost the conduits as is ordinarilyrequired, and prevents the rapid formation of frost on the pipes, andthe absorption of moisture from the food products. Further, my inventionresults in great economy in power, as electric current is running therefrigerator to maintain a predetermined temperature as in therefrigerators heretofore used more power is required to operate therefrigerator to maintain a given temperature as the frost forms on thecoils as the frost acts as an insulator.

What I claim is:

1. In a refrigerator comprising a cabinet having refrigerating coilsarranged near the top and one side wall and spaced apart therefromforming air passages between the top and side walls and the coils, and ablower near and spaced apart from the top of the cabinet and from saidcoils and having its outlet arranged to discharge toward the passagebetween the coils and the'top wall, for forcing unrefrigerated air in ahorizontal direction over the coils to create an ejector action to suckrefrigerated air in and about the coils upwardly into the horizontalpassage against the action of gravity, said fan having its intakearranged to receive part of the warmer air current passing upwardly fromthe lower part of the cabinet.

1 2. A refrigerator comprising a cabinet having top, bottom, and sidewalls, refrigerator coils located in the upper portion of the cabinetnear the top wall and the opposite side walls and spaced apart from thetop and side walls forming air passages, a blower located in the upperpart of the cabinet near the top wall thereof and between the coils, theblower having outlets discharging laterally into the space between thetop wall and the coils, and an intake located at a till level betweenthe coils and arranged to receive air from the lower portion of thecabinet, said blower casing air currents having an injector actionsucking the colder air upward laterally and downwardly along oppositesides of the cabinet to the lower portion thereof where it receives heatfrom the lower part of the cabinet and then upwardly between and aboutthe coils, a part of the upward current passing through the blower.

3. The method of preventing rapid formation of frost on therefrigerating conduits of refrigerating units of refrigeratorsconsisting in forcing unrefrigerated air in a continuous path over andaround a refrigerating unit and out of contact with the same and causingrefrigerated air about the conduits of the refrigerating unit to besucked upwardly against gravity through the refrigerating unit, andmixing the refrigerated air with the unrefrigerated air before the mixedair contacts with the articles to be cooled.

4. The method of preventing rapid formation of frost on therefrigerating conduits of refrigerating units of refrigeratorsconsisting in forcing unrefrigeratedair in a continuous path in ahorizontal direction above a refrigerating unit and around the same andout of contact with the conduits of the unit, creating an ejector actionabove the refrigerating unit by the horizontal path of theunrefrigerated air and causing the refrigerated air about the conduitsof the refrigerating unit to be sucked upward against gravity throughthe refrigerating unit, and mixing the refrigerated air with theunrefrigerated airbefore the mixed air comes in contact with thearticles to be cooled.

5. The method of preventing rapid formation of frost on therefrigerating conduits of refrigerating units of refrigeratorsconsisting in forcing unrefrigerated air in a continuous path over andaround a refrigerating unit and out of contact with the same and causingrefrigerated air about the conduits of the refrigerating unit to besucked upwardly against'gravity through the refrigerating unit, mixingthe refrigerated air with the unrefrigerated air before the mixed aircontacts with the articles to be cooled, and displacing the air warmedby the heat absorbed from the contents of the refrigerator, upward toreplace the refrigerated air removed from and about the conduits causinga continuous current of air to pass upwardly through the refrigeratingunit and counteracting the tendency of refrigerated air to fall.

6. A refrigerating apparatus including a cabinet having refrigeratingcoils in the upper portion thereof spaced from the top and side wallsproviding horizontal and vertical cold air passages and means forcausing unrefrigerated air to positively and continuously pass laterallyinto the horizontal passage over the refrigerating coils to the verticalpassage and then downwardly to displace upwardly the air in the lowerareas of the cabinet, the unrefrigerated air passing over the coilscreating an ejector effect and causing the refrigerated air to be suckedupwardly against gravity and mixed with the unrefrigerated air as thelatter moves downwardly in the said vertical passage and before themixed air contacts with the articles to be cooled.

GEORGE H. KLIPPEL.

